This invention relates generally to devices and systems for automatically watering one or more potted plants. More particularly, this invention relates to an improved automatic watering device designed for delivering water in response to the weight of a potted plant which indicates the moisture content of the plant soil, wherein the watering device can be adjustably set quickly and easily to provide specific weight-responsive set points for turning the water flow on and off.
Automated watering devices are generally known in the art for periodically delivering irrigation water to a potted plant. In one common form, the watering device includes a timer for operating a water flow valve at programmed time intervals to water the plant. Such devices, however, inherently deliver water to the plant according to the timed schedule without regard to actual plant need which can and frequently does vary significantly in response to changing humidity and variable sunlight conditions as well as the presence of natural rainfall. To account for these variables while preventing undesirable under-watering, time-function watering devices are usually operated in a manner maintaining the plant in an over-watered condition. Unfortunately, plant over-watering is not suitable for optimized plant growth and associated root development.
Alternative devices for watering a potted plant have been developed, wherein a water flow is turned on and off in response to weight which is reflective of plant and soil moisture content. In watering devices of this type, the potted plant is typically suspended or hung from a spring-loaded hanger adapted to sense the weight of the potted plant and to respond thereto for opening and closing a water flow valve. See, for example, U.S. Pat. No. 4,825,591 and British Patents 2,190,573; and 2,246,418. In general, however, these weight-response watering devices have been relatively complex in construction and operation, particularly with respect to adjustment of specific weight-responsive set points applicable to a specific plant type, size, and weight. Moreover, such devices have tended to turn the water flow on and off within a narrow weight range resulting in minimal variation of soil moisture content, and thus not creating a more natural prolonged dry interval conducive to optimal root development. Copending U.S. Ser. No. 08/594,800 discloses an improved watering device of the weight-responsive type, capable of providing a desired longer dry interval between watering cycles, but wherein the volume or weight of water delivered during each watering cycle is essentially fixed and thus not conducive to convenient adjustment to suit the needs of a particular plant type and size.
There exists, therefore, a continuing need for further improvements in and to devices and systems for automatically watering a potted plant, wherein water flow to the plant is turned on and off in response to specific and relatively easily adjusted weight-responsive set points. The present invention fulfills these needs and provides further related advantages.